Drying mechanism.



W. R; MACKLIND.

DRYING MECHANISM. APPLICATIOVN FILED AUG. 10. 1912.

1,191,921. 1 Patented Ju1y18,1916.

l2 SHEETS-SHEET lvy ITNE$SES= INVENTOE RI MACKLIND.

DRYING MECHANISM.

APPLICATION FILED Aue.1o. 1912.

Patented July 18,1916.

12 SHEETS-SHEET 3- w. R. MACKLIND.

.DRYING MECHANISM.

APPLICATION FILED AUG. I0, 1912.

Patented July 18, 1916.

I 2 SHEETS$HEET 4.

W. R. MACKLIND.

DRYING MECHANISM.

APPLICATION FILED AUG. 10, 1912.

Patented July 18, 1916.

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DRYING MECHANISM.

APPLICATION FILED AUG. 10, 19:2.

I 2 SHEETSSHEET 6.

H free/v2 Y- Patented July 18,1916.

'W. R. MACKLIND.

DRYING MECHANISM. APPLICATION FILED AUG. 10. l9l2. v

- Patented July 18, 1916.

I2 SHEETS-SHEET 7- HTTQB/VE Y- W. R. MACKLIND.

DRYING MECHANISM.

APPLICATION FILED Aue.|0. 19m.

Patented July 18, 1916.

12 SHEETS-SHEET 8.

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W. R. MACKLIND.

DRYI NG MECHANISM.

APPLICATION FILED AU G.10|19I2.

Patented July 18, 1916.

12 SHEETS-SHEET 9.

III N W/T/VESSE I I #vwavraz- I Q6 6% 61 MAW 54 w. R. MACKLIND.

Patented July 18, 1916.

12 SHEETS-SHEET 10.

.W. R. MACKLIND.

DRYING MECHANISM.

APPLICATION FILED Aue.10. 1912.

P11611161 July 18, 1916.

12 SHEETS-SHEET 11.

W. R. MACKLIND.

Patented July 18, 1916.

12 SHEETS-SHEET 12.

. useful Improvement in Drying Mechanism,

UNITED ST TES PATENT orrron.

WILLIAM R. MACKLIND, OF CLEVELAND, OHIO, ASSIGNOR TO GEORGE A. MARTIN,

TRUSTEE, 0F CLEVELAND, OHIO. I 4

DRYING MECHANISM.

Specification of Letters Patent.

Patented July 18, 1916.

T 0 all whom it may concern Be it known that I, IVILLIAM R. MACK- LIXD,a citizen of the United States, and a residentof Cleveland, county ofC-uyahoga, and State of Ohio, haveinvented a new and of which thefollowing is a specification, the principle of the invention beingherein'explained and the best mode in which I have contemplated applyingthat principle, so as to distinguish it from other inventions.

The present invention, relating, as indicated, to drying mechanism, hasas its object the provision of a drying machine capable of handling wet,sludgy materials, which are known in commerce as pulps, both in mineraland vegetable products. For example, such pulp, as is well known, isproduced in the manufacture of white lead and lead oxid, zinc oxid andother pigments. All of these materials when in the pulp state are moreor less refractory, both in being subjected to drying means, and inletting loose of a-certain percentage of the water which they "carry. Inthe first instance the difficulty is infeeding, as the pulp must beconstantly agitated. and then placed on drying means in a consistentform, or manner, or

the drying will be unequal and hence unsatisfactory. In the secondinstance, even when relatively high temperatures are applied, owing tothe tendency of their exterior or more exposed surfaces to dry first andso harden as to render the drying of the interior of the mass extremelyslow and diflicult.

By the improvements constituting the present invention, I propose notonly to ac-. complish the quick and thorough drying of materials of thekind described, but I also propose to render such drying a continuousprocess so that there need be no interruption in the handling of thematerial, the wet sludge, or pulp, being supplied in a continuous streamto the drying machine, and the dry powdery product being similarlywithdrawn. By this continuous and rapid method I will greatly reduce thecost of evaporating the waterfrom the pulp which cost under presentmethods is very high, due to low eiiiciency of machines in use, and timethey require to accomplish the drying.

It is a further object of the invention to provide against the escape ofsuch dry powder into the surrounding atmosphere, this being highlyobjectionable in handling polsonous products, such as white lead; asalso to provide for the collection and withdrawal of the vapors risingfrom the drying operation proper, so as to render it convenlent andhealthful towork about the machine.

To the accomplishment of the foregoing and related ends, said invention,then, consists of the means hereinafter fully described and particularlypointed out in the claims.

The annexed drawings and the following description set forth in detailcertain mechanlsm embodying the invention, such disclosed meansconstituting, however, but one trated in Fig. 1; Fig. 1 is a part planand part horizontal sectional view of one of the sections of the dryingtable which forms a feature of said mechanism; Fig. 5 is a sideelevational view of a trolley employed in.

supplying electrical current to various motive devices included in themechanism; Fig. 6 is a plan view of a trolley track wherewith saidtrolley contacts; Fig. 7 is a verti cal sectional view of the motor andconnect ed gearing whereby the mechanism as a whole is drlven; Fig. 8 1sa side elevational view of such gearlng; Fig. 9 1s a front elevation ofthe apparatus for feeding the material to be dried .onto the dryingtable; Fig.

10 is a side elevation and transverse vertical sectlon of the same;.F1g.11 1s a more or less dlagrammatic view illustrating the (lIlV ingconnections for operating saidfeeding apparatus; Fig. 12 is a plan viewof said feeding apparatus; Fig. 13 is a transverse sectional view of'the foregoing taken on the line 13"13, Fig. 12, and showing certainoperating levers in ele 'ation; Fig. 14 is a side elevational view ofone of said operating levers detached from the others. and

showing the connections between the lever and the valve which itoperates; Fig. 15 1s a horizontal sectional view of the apparatus forremoving the dried material from the table; Fig. 16 is a transversesectional view of such removing apparatus taken on the line 16-16, Fig.15; Fig. 17 is a vertical line 1919, Fig. 17; Fig. 20 is a plan view,

with parts shown in section, of a suction apparatus associated with saidmaterial removing apparatus and designed to prevent the escape of dustincidental to the removal of the dried material from the drying table;Fig. :21 is a side elevational view and partial section of such suctionapparatus; Fig.

22 is a transverse sectional view in a vertical plane of the operatorsplatform from which the operation of the mechanism as a whole. togetherwith the operation of its several parts, is controlled; Fig. 23 is atransverse sectional view of a portion of the vapor collecting apparatuswhereby the vapors arising from the drying material are removed; andFig. 21 is a more or less diagrammatic view illustrating one approvedmethod of feeding the material to be dried to the feeding apparatus ofthe machine.

The general features of construction characterizing the illustrativeform of my improved machine shown in the foregoing drawings comprisefirst an annular, substantially horizontally disposed drying table inconnection with which suitable heating means are provided. Incooperative relation to said table are then provided a feeding apparatusfor depositing onto the table a layer or film of the material to bedried; an apparatus for removing the vapor or moisture arising from thedrying of such deposited material; and an apparatus for removing fromthe table the dried material and discharging the same from the machine.

The foregoing features will be described in the order in which they havejust been noted, along with incidental items of frame structure andassociated operative details.

The drying table A, as already indicated, is of annular form and issupported by means of a series of suitable supporting stands 1 upon thefoundation :2, (Figs. 2 and The table proper is built up of a pluralityof contiguous sections that are supported upon said stands by means ofinner and outer channel rings 3. The sections therefor.

are in the form of sectors 4 and are hollow, the upper and lower wallsbeing connected together by webs, 5 as shown in the figures just namedand in Fig. 4c. Pipes 6 and 7 for supplying steam and removing the waterof condensation, respectively, are provided in connection with eachsector, the last-named pipes being connected to the inner ends of thesectors and the bottom walls of the latter sloping toward such innerends so as to cause the condensed water to drain naturally away. Thesepipes are radially disposed and are connected at their inner ends tocircular headers 8 and 9, respectively; while a common steam supplysource is thus provided, it will be observed that the amount of steamsupplied to each sector is independently regulable so that thetemperature of the upper face of the assembled table may be regulated soas to vary at different points around the circle. Such upper face isdesigned to be smooth and polished and the sectors accurately joinedtogether so that a practicallyuninterrupted surface is provided aroundthe entire extent of the table.

lVhile the size of the table, that is the area ofits drying surface,will of course vary with the capacity desired, I have found itadvantageous to preserve a certain relation between said tables' innerand outer diameters in order to secure the best and most uniform dryingresults. It is accordingly recommended that the minimum ratio 1 more, inorder thatthe material feeding and removing apparatus may operate wellwithin the edges of the table thus insuring against the escape ofmaterial over such edges, the latter are made to extend beyond the edgesof the hollow heating-chambers so that the surface of the table will beflanked, both on the inside and the outside, by a nondrying space.

Substantially all the remaining parts of the drying machine are in thepresent construction supported by a rotatable frame (Fig. 1), whichcarries such parts in proper cooperative relation to ithe table and alsosupports the necessary operating mechanism It will be understood, ofcourse, that if found feasible, by reason of variation in size, or forother reasons, to rotate the ciples of operation involved are concerned.

The center of said rotatable frame is a cast iron spider 1O rotatablymounted on a central column 11 having a. flanged top and a centeringsleeve 12, (Figs. 2 and 3). A ball bearing is interposed between theunder face of the spider and said flange, while a roller bearing 14: issimilarly provided between the centering sleeve and an internal annularadapted to run.

flange 15 of the spider. While the-latter is thus securely mounted onthe centering column, it is nevertheless, possible, by simply raisingthe same a short distance, as is entirely feasible by means'of jacks orthe like, to lift the centering sleeve 12 and thereby withdraw the ringsor raceways of the ball bearing for the purpose of repair or renewal.This construction at the same time facilitates similar attention beinggiven to the roller bearing 14, since by raising the sleeve the rings ofthe latter bearing are longitudinally spaced.

A plurality of arms 16, fabricated of structural steel, extend radiallyfrom spider 10 to beyond the outer edge or periphery of the annulardrying table, such outer arm-ends being spaced from the surface of thetable a sufficient distance to provide the necessary clearance for theparts suspended therefrom, as will be'presently described. Two series offrame struts, an outer series 17 and an inner series 18, are bolted tosaid radial arms, the former to the extreme outer ends of the arms, andthe latter at a point substantially the same radial distance from thecentral axis of the machine as the inner edge of the annular table. Itis not intended to support the entire weight of this rotatable franiefrom the central column 11, but, at least in a large machine such as theone illustrated,

a circular track 19 is provided on the outer stands 1 of the annulartable. Upon this track rollers 20, that are mounted in brackets 21extending downwardly from the outer ends of the respective radial arms16, are

same circular track is provided an annular rack 22 having its teethdirected inwardly, such rack being utilized in effecting the, rotationof the frame, as shown in detail in Figs. 7 and 8. To this end there isprovided a pinion 23 that meshes with said rack, said pinion beingcarried by the lower end of a vertically disposed shaft 21 secured insuitable bearings 25 and 26 in the outer end of one of the radial armsof the frame and on the adjacent bracket 21,- respectively. electricmotor 27 supported on 'such arm serves to drive this shaft 21 throughthe medium of a sprocket chain 28, shaft 29 and worm gearing 30.

The apparatus B for feeding the material to be dried onto the dryingtable, and the apparatus C 'for removing such material after it has beendessicated, are both desirably supported from the rptary frame justdescribed in rather close relation. Hence as will appear from the planview of Fig. 1, the removing apparatus is attached to and directly underone of the radial arms 16, while the feeding apparatus is supported fromthe inner and outer struts 17 and 18 that join the aforesaid radial armwith the one next following after, having regard to th 11 In connectionwith thistion of rotation of the frame as av whole, which is indicatedby the arrow in the figure just referred to. Not only may a singleoperator thus supervise both the feeding and removing apparatus, butsubstantially the entire extent of the table is available for dryingpurposes, the layer of wet material being spread on said tableimmediately following the removing apparatus, which takes up and carriesaway the previously deposited layer, now dried. 1

For the accommodation of the operator a platform -31 is providedparallel with the outer strut 17 from which the feeding apparatus B issupported, and a crossing 32 is disposed at right angles to saidplatform between said feeding apparatus and the removing apparatus C, sothat the operator can, if necessary, reach any portion of both.

The sludge, or equivalent material to be dried. is conducted to thefeeding apparatus B from a central vertically arranged tubular column 33that has an upper flanged end and is laterally inclosed by a relativelystationary section 3-1 of a vapor drum, to which more particularreference will be hereafter made. The flanged end of the column 33 hasbearing contact wlth the annular base of a support 35' for a connectionor union 36 whereby an exterior-1y supported supply pipe 37 (shown inFig. 21), is joined with 'a supply p1pe 38. carried by said column andconnected by means of an elbow at the lower end of the latter with aradially disposed.

pipe 39 that leads out to the feeding ap-, paratus. The column 33 issupported in the fashion just described by means 'of a spider 10, thearms of which are attached.

at their outer ends .to the lower section 11 of the aforesaid vapordrum. such section being attached to and rotating with the main, frameof the machine.

In the feeding apparatus B, the sludge from supply pipe 3.9.is initiallyreceived in a tank 12 from which it is subsequently discharged onto afeeding table 13. all fully shown in Figs. 9 and 10. Said-tank 12 isprovided with an inlet opening 11 on top for connection with the supplypipe and is provided on its bottom side with a plurality .of outlets 15(six as shown) separately controlled by means of valves :16. All ofthese valves are conveniently operable from the operator's platform 31by means of connecting rods 17 that lead from the valves to a bank oflevers 18 at one end of the feeding apparatus adjacent to such platform,(see Figs. 12, 13 and 1-1). said connecting rods being formed with shortracks 19 adapted uniform thickness to be spread across the table. Anagitator 51 within the tank serves tostir up the contents of the latterand maintain the mixture of uniform consistency, said agitator beingoperable by means of a hand wheel 52 at the outer end of its shaft 53. I

It will be understood that the supply tank 42 is not only kept full ofmaterial, but that such material is desirably maintained .under aconstant head so as to insure an unvarying rate of feed from the severalvalve-controlled outlets. with any given adjustment of said valves. Suchconstant head may be securedby means of the arrangement illustrated inFig. 24:, which diagrammatically shows the supply tank just described,together with the connecting pipes 38 -and.39 carried by the rotatableframe. Ata point removed from the machine, a pump 5A is connected withthe exteriorly supported pipe 37 that is connected with the stufling boxor union 36, such pump discharging more directly into a stand-pipe thatconnects the same with said pipe 37 and has an overflow 56 ofpredetermined elevation back into the tank 57 from which the supply ofmaterial for the pump is drawn. If, accordingly, the pump be governed tosupply an excess of material, that is more than will be withdrawn fromthe supply tank 42 carried by the drying machine, the sludge in suchsupply tank will be under a constant pressure determined by theelevation of the upper end of the overflow pipe 56.

The feeding table 43, that receives the material from the severaloutlets 45 of the trough-like receptacle formed by said plate wells upbetween the front face of the latter and the frontwall of the'depressionunt-il it overflows the crest of such depression and thenruns down over the lower edge of the inclined plate 4.3.

The entire feeding table, or shaker board,

as it may \be called, is oscillatorily hung from the supporting frame ofthe machine by means of tlowhwardly depending brackets 61 (see Fig. 10),to which the end plates and other intermediate plates 62, that areattachedto the shaker board, are hinged.

' The excess of weight liesin front of the pivotal axis thus formed soas to normally retain the rear ends of the side plates 60 andintermediate plates 62 (which are extended for this purpose).inengagement with cams 63 on a. longitudinally disposed cam shaft 64:.Such shaft is rotated by a suitable motor 65 disposed adjacent to theinner end of the feeding apparatus and belted to a pulley 66 on theshaft, as shown in Figs. 1 and 11. 'Cams 63 will obviously serve tooscillate the table about its pivotal axis and incidentally jar thesame, hardened plates 67 being provided on the cam-engaging ends ofplates 60 and 62 to receive the wear. Along the lower edge of the shakerboard, finally, there is provided a series of equidistantly spaced-teeth 68. Accordingly, while 'the material overflows from the trough inthe form of a broad flat ribbonlike stream of uniform depth, the effectof these teeth is to break up this broad stream into a multitude of tinystreams that trickle the material onto the drying table in the form ofdrops. The object, in other words,

is to supply these drops in such size and frequency and spaced relationas to just spfead over the surface of the table and no more, since Ihave found that a layer deposited in this fashion dries much morereadily than if deposited as a sheet or ribbon, each little drop ofmaterial drying out independently of the other.

The apparatus for removing the dried material is shown in detail inFigs. 16 to 19 inclusive and consists essentially of a brush 70 adaptedto contact with the surface of the drying table A and followed by one ormore scrapers 71 which gather up the material loosened by the brush, twosuch scrapers be- 'ing employed in the machine illustrated.

Both the brush and the scrapers are inclosed in a tight casing 72 thatsurrounds the same on all sides having close fittingcontact with thedrying table at its outer and inner edges, and depending intosubstantial contact with the surface of the same on either side of theremoving apparatus. Such contact, in the case of the inner table edge,is secured with the under surface of such edge, which projects beyondthe body of the table with this object in view, the casing 72, or ratherthe hopper 91 extending downwardly therefrom, being provided with aninwardly bent lip 73 faced with packing material. Close contact, inthecase of the front and back sure exerted by the brush on the dryingtable may be varied, as desired. Each scraper consists of a strip ofthin metal attached to the lower edge of an angular trough member 76that is hung from the spindle 77 of a, conveyer screw 78 disposed to fitsnugly in said trough member. Rods 7 9, connected with brackets 80thatproject rearwardly from the conveyer troughs, extend upwardlythrough the top of casing 72 where they are secured by nuts 81,compression springs 82 being interposed between said nuts and casing. Bymeans of these nuts it'will be evident that adjustment of the scrapersrelatively to the surface of the v drying table may be made. For thepurpose of driving or rotating the brush and the conveyers they areprovided at their inner ends with a series of sprockets 83, 84 and 85which are connected with a corresponding series of sprockets 86, 87 and88 on a jack-shaft 89 driven from a motor 90 as shown in the plan viewof Fig. 1 and in the side elevational view of Fig. 18.

In operation, it will be understood that the brush is designed simply toloosen and render fragmentary the layer or deposit of dried material onthe table. The first scraper 71 will then pick up substantially all ofsuch loosened material, the second being merely provided to insurethethorough and complete removal of the material. The I conveyers 7 8, inoperative conjunction with the scrapers, carry the material to the innerends of the scraper troughs 76 so as to discharge the material into ahopper 91 that is suspended from and integral with the adjacent end ofthe casing 72 inclosing the removing apparatus. This hopper has a closefitting contact with the under edge -of the table, by .virtue of the lip73 of the casing, previously described, so that no dust 'can escape;

Leading from the hopper is a conveyer trough 92, radially disposed withrespect to the axis of the machine and having a screw conveyer 93whereby the material received in; said hopper 91 is ca'rried to an innerconical hopper 94 formed integrally in the central column 11 whereon therotatable frame of the machine is supported. This hopper 94 opens at itslower end into anannular closure 96 having a tight detail in Figs. 17and 19. A tight, dustproof fit between this closure and the flanges 97is insured by the use of packing rings 98 that are held in contact withthe flanges by means of resilient members 99.

The driving of the screw conveyer 93,is accomplished by means of thesame motor 90 that drives the removing apparatus C, proper. T 0 this endanother sprocket 100 is provided on jack-shaft 89 (Fig. 1), saidsprocket being connected with a sprocket 101 located below the trough 92that is in turn connected with the conveyer by intermediate gearing 102.

Despite the fact that the casing 7 2 that incloses the removingapparatus, proper, fits the drying table A as closely as possible, therewill, nevertheless be some dust or finely powdered material escapeintothe outer atmosphere unless additional precautions be taken. Suchadditional precautions comprise a suction fan 103 (Figs. 1, 3, 20 and21) connected to be driven from the same jack shaft 89 as theremoving-apparatus C and conveyer 93 just described, by means of a belt101. .The intake to such dust. fan

leads from the casing 72 that incloses the aforesaid apparatus, whilethe discharge takes place into a dust collector head 105 from whichdepend a plurality of bags 106, of familiar construction, which allowthe air to pass readily through but retain any. dust that may be carriedthereby. The lower ends of the bags are normally tied shut, but when asufficient amount of dust accumulates therein to render such proce-'branches 109 therewith.

By the foregoing described means the dust which is collected by the fanis j oinedto the bulk of the material that is directly carried off bythe removing apparatus. It will be understood that only a moderatesuction requires to be produced by the fan, the only object being'toproduce a slightdraft at the joints where the casing 72, that inclosesthe removing'apparatus, fits the edges and surface of the drying table.This will serve to prevent any dust escaping into the outeratmosphere,with out'imposing on the fanthe duty of removingany.considerable body of a the material.

It will be understood that the drying table of the machine has aconsiderable superficial area, and there will be produced in dryingmaterials, such as those in mind, such a considerable volume of vapor orsteam as to be objectionable, especially under certain weatherconditions and in buildings more or I less inclosed. Iaccordinglyprovide means for withdrawing and removing from the apparatussubstantially all such vapor, said means comprising a series of vaporcollectors discharging into the central drum made up of the stationarysection 34 and the rotatable section 41, hereinbefore described. Thecollectors themselves are in the form of hoods disposed betweensuccessive radial arms'of said frame and are all similar with theexception of one of special construction that is mounted next to thefeeding apparatus B. Each of said similar collectors is made up of twoside members 110 and a central key-member 111- .supported from theradial arms 16 by means ofrods 112 (Figs. 1 and 2) as need not beexplainedin detail, the lower edges lying close to the upper surface ofthe drying table. The specially constructed collector 113 adjacent tothe feeding apparatus is shown in transverse section in Fig. 23 anddiffers from the other duplicate sections only in the matter of size,consisting of a single member which is furthermore provided at itsforward edge with an extension that projects under the shakerboard 43and substantially even with the fore edge thereof, so that the. va orproduced by the material dropping rom the shaker-board onto the dryingtable is.immediately caught by the collector. This is highly importantfor the reason that obviously the greater bulk of the vapor driven oflduring the drying operation is driven off at this stage, less and lessevaporation occurring as the drying progresses. Leading from thisspecial collector 113 adjacent to the feeding apparatus and from thecentral member 111 of each of the duplicate collectors, is a radialvapor-pipe 11 1 that is connected with the rotatable section 41 of thecentral vapor drum. A water-sealed joint 115 forms a tight closurebetween this section and the upper stationaryise'ction 34 of said drum,with which lattersection is connected the main discharge vapor pipe 116.Said pipe 116 may lead to any suitable point without the buildingor-structure in which the drying machine is housed. Ahsuitable draftshould be induced in this vapor discharge pipe either by means of a fan117 or the like located at its outer end, as shown in Fig. 2, or byconnecting such outer end with a stack, all as will be readilyunderstood;

Inasmuch as the vapor will naturally tend to condense more orless,incidentally to its collection by the pipes 113 and the drumintowhich they discharge, such pipes are arranged to incline downwardlytoward the drum, and the latter is provided in its bottom with drainpipes 118 that lead to an annular trough 119.supported upon the centralcolumn '11 by means of the centering sleeve 12. This trough is, in turn,provided with a drain pipe 120 thatleads to a central pocket 121 in thecolumn having an exterior discharge (not shown).

Current for the operation of the several motors, which are carried bythe rotating frame of the machine, viz., motor 27, which serve to drivethe frame itself, motor which operates the feeding apparatus, and motor90 which operates the removing apparatus, together with the conveyerleading therefrom and suction fan 103, is supplied from circular tracksor trolleys 122 supported on arms or brackets 123 that extend radiallyfrom the central column 11, see Figs. .1, 5 and 6. Such tracks 122 aresuitably insulated from the arms and are connected with leads from theexterior circuit, of which no showing is deemed necessary. Pivotallysupported from a pair of brackets 121, attached to the-under side of oneof the arms 16 of the frame, so as to be carried around therewith, arecontact shoes or trolleys 125 which contact with circular tracks 122,respectively, said shoes being insulated from the frame as is shown inFig. 5. These shoes are'resiliently pressed against the tracks by meansof springs 126, and from them are led the conductors 127, which supplythe current to the several motors previously referred to. It has notbeen thought necessary to illustrate the detailed wiring connections, orcircuits for said motors, as these will be'readily understood. It shouldbe added, however, that the switches and rheostats 129, interposed inthe motor cir- 'cuits for controlling the current supplied to each ofthese motors, are mounted at points conveniently adjacent to theoperators platform 31, (see Figs. 1 and 22). In this way, not only maythe operator directly supervise and adjust the feeding apparatus B andthe removing apparatus C from said platform, but he also has directly athand these switches and rheostats for controlling the speed at which themachine frame rotates, as well as the speed at which each apparatusshall be operated; .7

The general operation of the machine just described will only requirethe briefest attention, such operation having been in the main clearlyindicated by the description of the several component parts and mechanisms' that enter into the construction of said machine. Assuming that asuitable supply of material is being furnished under a predeterminedhead by' pump 5-1 (Fig. 24) and, that the feeding apparatus B has beenproperly adjusted by means of the several levers 48 which control thevalves 46, a thin film or layer' of the sludge or other material to bedried, will be deposited on the will not be deposited stricly as asheet, but

will consist of a collection of tiny drops, which, although theycoalesce as they fall onto the drying table, nevertheless preserve theirindividuality sufliciently to dry separately, each forming a tiny craterwhereby the prompt and thorough drying of the deposited layer as a wholeis insured.

In the operation of the machine, it has been previously indicated thatthe removing apparatus C immediately precedes this feeding apparatus B,such removing apparatus breaking up and carrying to the inner edge ofthe annular table the layer of niaterial deposited upon the .previousround.

This dried material, as it drops over the inner edge of the table, iscaught in the hopper, or chute 9.1, and is thence carried by conveyer 93to the central hopper 9i, and so away out of the machine.

By means of the suction fan 103, the air pressure within the casing 72,which incloses the aforesaid removing apparatus, is

lowered sufiiciently to prevent the escape of any dust that may becaused by thebreaking up of the material under the action of therevolving brush 7 Oand the scrapers 71. It is not the object, however,of this fan to create so strong a suction as to carry from the branchedtrunks 108 more than a minimum amount of the material, incidentally tothe accomplishment of the foregoing object. This dust is collected inthe bags 106 and added from time to time to the greater bulk of thematerial that is being constantly conveyed to the central hopper by theconveyer 93.

It has been pointed out that the particular machine, chosen for thepurpose of illustrating the invention, is a relatively large one,adapted for the handling of a considerable quantity of sludge, andcertain of the features hereinbefore described are more particularlyadapted for use in connection with a machine of suchlarge size andcapacity. It is not intended, however, to imply .by this that themachine is not equally adaptable for, use in operations of a smallerscale, and in handling other materials thanthe particular one in handand in such cases various modifications will readily suggest themselves,and it may also be unnecessary to utilize all of the featurescharacterizing the complete apparatus herein illustrated and described.By means, however, of such machine, even reduced toits fewest essentialelements, a very much more rapid and eflicient drying of materials ofthe general class previously referred to is obtainable: even the morerefractory yield up their'content of Water completely and all conditionsare arranged to hasten evaporation so far as possible. The machine isfurthermore highly flexible in operation, being readily accommodated notonly to materials of different characters but also to differentconditions of material and otherwise. Finally where poisonous materialsare being handled, the ability to confine all dust and convey thematerial from the machine without exposure of the operator in any way ishighly important not only to his health but convenience as well.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed.

I therefore particularly point out and dis.- tinctly claim as myinvention '1. In drying mechanism, the combination of an annular dryingtable; a column centrally disposed with respect to said table; avertically removable sleeve mounted in such upper column end; a framecomprising a central spider surrounding said sleeve and radial armsextending over said table; said spider being rotatably supported uponsaid column; and material feeding and removing meanscarried by saidframe in operative relation to said table.

2. In drying mechanism, the combination .of an annular drying table; acolumn centrally disposed with respect to said table; a verticallyremovable sleeve mounted in such upper column end; a frame comprising acentral spider surrounding said sleeve and radial arms extending oversaid table; means rotatably supporting said spider from said column; andmaterial feeding and removing means carried by said frame in operativerelation to said table.

3. In drying mechanism, the combination of an annular drying table; acolumn centrally disposed with respect to said table and laterallyflanged at its upper end; a vertically removable sleeve mounted in suchupper column-end; a frame comprising a central spider surrounding saidsleeve and radial arms extending over said table; ballbearingsinterposed between said spider and theflaiige on said column, wherebysaid frame is rotatably supported on the latter; and material feedingand removing means carried'by said frame inoperative relation to saidtable.

4. In drying mechanism, the combination of an annular drying table; acolumn centrally disposed with respect to said table and laterallyflanged at its upper end; a vertically removable sleeve mounted in suchupper column-end; a frame comprising a central spider surroundingsaidsleeve and radial arms extending over said table; ball-bearingsinterposed between said spider and the flange on said column,-Wherebysaid frame is rotatably I supported on the latter; roller bearingsinterposed between said spider and said sleeve; and material feeding andremoving means carried by said frame in operative relation to saidtable.

5. In drying mechanism, the combination of an annular. drying table; aframe rotatably supported on said table; material feeding and removingmeanscarried by said frame .in operative relation to said table;electric motors for operating said feeding and removing means; andelectric connections for said motors including circular trolley-tracksat the center of said table and trolleys carried by said frame andcontacting with said tracks.

6. In drying mechanism, the combination of an annular drying table; acolumn centrally disposed with respect to said table; a frame rotatablysupported onv said column and extending over said table; materialfeeding and-removing means carried by said frame; electric motors foroperating said feeding and removing means; and electric connections forsaid motors including circular trolley-tracks supported 'from saidcolumn and trolleys carried by said frame and contacting with saidtracks.

7. In drying mechanism, the combination of an annular drying table; acolumn centrally disposed with respect to said table; a frame rotatablysupported upon said column and comprising radial arms extending oversaid table; material feeding and removing means carried between two ofsaid arms in operative relation to said table; an

'operators platform supported from said arms'adjacent to said feedingand removing means; electric motors for operating the latter; electricconnections for said motors including contact means with an exteriorcircuit; and current controlling means in said connections located oversaid platform.

8. In drying mechanism, the combination of an annular drying table; acolumn centrally disposed with respect to said table; a frame rotatablysupported upon said column and extending over said table; materialfeeding and removing means carried by said frame in operative relationto said table;

said removing means being disposed in advance of said feeding meanshaving regard to the direction of rotation of said frame; and vaporcollecting means carried by said frame between said removing means andfeeding means, having regard to such direction of rotation.

9. In drying mechanism, the combination of an annular drying table; acolumn centrally disposed with respect to said table; a frame rotatablysupported upon said column and extending over said table; materialfeeding and removing means carried by said frame in operative relationto said table;

said removing means being disposed in advance of said feeding means,having regar to the direction of rotation of said frame; connectionsleading from the central axis of said table to said feeding means;conveying means leading from said removing means to such axis; saidconnections and conveying means being both carried by said frame; andvapor collecting means carried by said frame between said removingmeansand feeding means, having regard to such direction of rotation.

10. In drying mechanism, the combination of an annular drying table; acolumn centrally disposed with respect to said table; a frame rotatablysupported upon said column and extending over said table; materialfeeding and removing means carried by said frame in operative relationto said table; connections leading from the central axis of said tableto said feeding means; conveyin'g means leading from said removing meansto such axis, said connections and conveying means being both carried bysaid frame; vapor collecting means carried by said frame between saidremoving means and feeding means, having regard to such direction androtation; and a centrally located vapor drum connected with said vaporcollecting means.

11. In drying mechanism, the combination of an annular drying table; acolumn ,in advance of said feeding means, having regard to the directionof rotation of said frame; connections leading from the central axis ofsaid table to said feeding means; conveying means leading from saidremoving means to such axis, said connections and conveying means beingboth carried by said frame; an axial feed pipe adapted to supplymaterial to be dried to said connections; a hopper in said columnadapted to receive the dried material from said conveying means; andvapor collecting means carried by said frame between said removing meansand feeding means, having regard to such direction of rotation, wherebythe vapor from the material spread on the table may be continuouslyremoved. Y

12. In drying mechanism, the combination of an annular drying table; acolumn centrally disposed with respect to said table; a frame rotatablysupported upon said column and extending over said table; materialfeeding and removing means carried by said frame in operative relationto said table, said removing means being disposed in advance of saidfeeding means, having regard to the direction of rotation of said frame;connections leading from the central axis of said table to said feedingmeans;

